Asbestos

Asbestos is a collective term given to a group of silicate minerals that occur in various fibrous forms. The mineral naturally occurs in deposits throughout the world and has a number of highly unique properties. For example, it has high degrees of flexibility, durability, and resistance to heat and chemical corrosion (1). Historically, these traits made the use of asbestos commonplace in several industrial sectors. Occupational uses of asbestos are known to occur among aircraft mechanics, electrical workers, shipyard workers, auto mechanics, cement workers, and railroad workers.

The six minerals that fall under the classification of asbestos are commonly grouped under two families of minerals known as serpentines and amphiboles (2). The serpentines are chrysotile (white asbestos). The larger amphiboles group contains amosite (brown asbestos), crocidolite (blue asbestos), anthophyllite, tremolite, and actinolite. The two groups are primarily distinguished by the manner in which they are processed in the lungs after inhalation. Specifically, chrysotile fibers are easily degraded in the lung and break apart easily, thereby behaving similarly to other non-fibrous minerals. However, the lungs' responses to the amphiboles suggest a more insoluble structure. Only chrysotile is currently mined in significant quantities for its myriad uses in industry.

A link was established between asbestos and lung disease in 1890, while the first attributable deaths were connected in 1907. The discovery of several other dire maladies from exposure was soon to follow. The United States enacted legislation in 1971 that limited exposure to asbestos. This followed similar action by British authorities in 1931. In 2004, the Collegium Ramazzini, an elite, international academic society of 200 fellows recommended the immediate cessation of all uses of asbestos (3). All 25 countries of the European Union, several South American countries, South Africa, and Japan are scheduled to impose such a ban. However, although curtailed, asbestos use in the United States continues.

'Asbestos' Sources:
  1. O'Reilly, K.A., et al., "Asbestos-related lung disease". Am. Fam. Physician; 75: 683-8, 690, 2007.
  2. Bernstein, D.M. and Hoskins, J.A., "The health effects of chrysotile: current perspective based upon recent data". Reg. Toxicol. Pharmacol.; 45: 252-64, 2006.
  3. Landrigan, P.J. and Soffritti, M., "Collegium Ramazzini call for an international ban on asbestos". Am. J. Ind. Med.; 47: 471-4, 2005.

 

 

 

 

 
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